VIDEO: Denver Protesters Cheered When Car Struck Officer

Denver high school students protesting recent civilian deaths involving police chanted "Hit him again!" after a car struck four bicycle officers - injuring one critically - Wednesday night, the city's police union charged.

Officer John Adsit of Denver PD underwent six hours of surgery Thursday for injuries sustained in the accident and was in critical, but stable condition. But the reaction of young students, reported by the Denver Post, left residents stunned and members of the Denver Police Protection Association angry. Students were heard chanting and cheering after the officers were hit. Teachers looked on and did not intervene while the students chanted, Fox31 Denver reports.

"The Denver Police Protective Association has learned that immediately after the horrible accident yesterday injuring four Denver Police Officers, several parties in the protesting group cheered and chanted 'hit him again.'" These actions are not only reprehensible but quite possibly the most disturbing thing this Association has ever heard," a statement released by the police officers' union Thursday night said.

The students were mainly marching in support of people protesting the shooting death of 18-year-old Michael Brown, who was killed by Officer Darren Wilson in Ferguson, Mo.

In a statement of its own, the Denver Police said it could not confirm the claims made by the union that students cheered when the officers were struck.

The student protest organizer says it was not students, but grown men who joined the protest march that cheered when the vehicle hit officers.